Suppose you have a steady current running through an inductor. If you attempt to reduce the current very quickly to zero by opening a switch, an arc (a spark) can sometimes appear at the switch contacts. Explain why in 100 words or less.

Self conductance in the circuit

Explanation:

Since most circuits have self conductance, coupled with inductance created by the flow of current with the circuit, makes it totally impossible to stop current immediately thereby causing arc to flash at switch contacts.